Incandescent lamp



June 14, 1938. v, J, RQPER 2,120,874)

INCANDESCENT LAMP Original Filed Ndv. 18, 1951 s Sheets-Sheet 1 I Inventor: Val J. Roper,

is Attorney.

J1me 1938. v. J. ROPER 2,120,87

INCANDESCEN'I LAMP Original Filed Nov. 18, 1931 3 Sheets-Sheet 2 Inventor Val J. Roper,

b 4 5% y Hl zttorny.

June 14, 1938. v; J. ROPER INCANDESCENT LAMP Original Filed. Nov. 18, 1951 5 Sheets-Sheet 3 6.? Z6. 6/ as as Fig. 27.

Invent o1 Val J. Roper,

b y His t'tornqy 1 Patented June 14, 1938 'rNcANoEscEN'r LAMP Val J. Roper, Cleveland Heights,

Ohio, assignor to General Electric Company, a corporation of Original application November 18, 1931. Serial No. 575,259.. Divided and this application .March 4, 1936, Serial N vember 23, 1937 0. 67,099. Renewed No- Claims. lotus-26) My invention relates to multiple filament incandescent electric lamps and more particularly to projection lamps comprising a plurality of filaments. My invention isparticul'arly applicable to vehicle headlights and the lamps used in connection therewith.

This application is a division of my application Serial No. 575,859, filed November 18,- 1931, which discloses combinations of light sources, lenses, and

reflectors which will produce various desirable road-illuminating beams. One of the objects of my invention is to provide lamps which, in combination with lenses or reflectors such as shown and described in my aforementioned application, will produce an asymmetric beam providing illumination along the right side of the road for use when approaching another vehicle, free from glare in the direction of the driver of said vehicle,

' but providing enoughillumination to reveal the arrange the filaments as boundaries-,of theroad as, well as'pedestrians or obstacles on the road itself, and from the same equipment a main driving beam for the open road which is substantially'symmetric laterally.

1 Another object. of my invention is to providea I beams another beam lamp which will produce in addition to these two in which substantially all light is directed below i the horizontal. Another object is to so shape and to obtain good control over the beams produced thereby. Other features and advantages of my invention will appear fromthe following description ofspecies thereof 1 and from the drawings. I

In the drawings Figs. 1' and 2 are elevations, taken 90 apart, of a lamp comprising my invention; Figs. 3 and 4 are similar elevations of a modification thereof; and Figs. 5 and 6 are similar elevations of another modification; Figs. 7 to 13 inclusive are diagrammatic'views showing the locations of the light sources in the reflectors as seen through the reflector from the driver's seat; Fig. 14 is a front viewof the right headlamp lens; Fig. 15 is a similar view of the left, headlamp lens; Fig. 16 is a vertical section along line lG-l 6' of Fig. 14; Fig. 1'7 is a similar section along line l'l-l'| of Fig. 15; Figs. 18 and 19 are horizontal sections along lines l8-'-l8 and [9-49 respectively of Fig. 14; Figs. 20 and 21 are similar sections along lines 20-40 and 2l-2I respectively of Fig. 15; Fig. 22 is a diagrammatic illustration of the driving beam pattern produced by the arrangement in either Fig. '7 or 8; Figs. 23 and 24 are similar views of the passing and city beam patterns respectively andareproduced by all the arrangements illustrated in Figs. 7 to 13 from the same equipmentinclusive; and Figs. 25, 26 and 27 are views of driving beam patterns resulting from the ar- 1 rangements shown in Figs. 9 'or 12, 10, and 11 or 13 respectively. 1

Referring to Figs. 1 to 6, the lamps comprise a bulb 2|, and a base 16, with positioning means such. as pins 20 mounted thereon to locate the lamps in the sockets of the reflectors. A pair of filaments Ill, ILpreferably V shaped, are located side by side on opposite sides of. the bulb axis and in a plane whichpasses through the saidbulb axis; Said filaments in, II extend laterally outward from the bulb axis and have the inner end of each connected to one end of a common lead wire I2 so that the two filaments together form a w. The other ends of filaments I0, I l are mounted on the ends of lead wires l3 and M respectively which, together with lead l2, have portions sealed in the stem l5 and are attached to portions of the base.

In the lamp shown in Figs. 1 and 2, a third rectilinear filament 22 is located out ofthe bulb axis in a plane which passes through the said bulb axis perpendicularly to the plane of filaments l0} II and is forwardly inclined at an angle of approximately 45 to said plane of filaments H), II. The said filament 22 is located directly to the side of filaments l0, ll so as to be directly above the focal point of the headlight'refiector when the lamp is mounted therein. One end of said filament 22 is mounted on the end of the common lead l2 and the other end is mounted on the end of a lead wire 23. I In Figs. 1 to 6 inclusive the common lead l2 isconnected to the base shell l6, and-the leads l3, M are connected to contacts ll, I8 respectively in the base. In Figs. 1 and 2 the lead wire 23 is connected to a contact 24 in the base.

' The lamp shown in Figs. 3 and 4 is similar to that in Figs. 1 and 2 except that in place of filament 22 in the latter, the former has a V-shaped filament located in aplane parallel to the plane of filaments I0, I I and spaceda small distance therefrom, the vertex of said filament 25 being located midway between the vertices of filaments Ill, II and at the same distance from the base or from the end o'f the bulb. i In other words, the said filament 25 is symmetrically disposed about a planeperpendicular to the plane passing through filaments Ill, ll so that said filament 25- is located directly above the focal point of the reflector when the lamp is mounted therein. One leg of said filament 25 is connected by a lead and support wire 26 to the commonlead wire l2 and the other leg is connected to a lead wire 21, the other end of which is con nected to the contact 24 in the base.

The lamp shown in Figs. 5 and 6 comprises, in place of filament 22 of Fig. 1 and filament 25 of Fig. 3, a V-shaped filament 29 located directly to the side of filaments III, II and in a plane perpendicular to the plane of said filaments of substantially the same size as said filaments, and at the same distance from the base or from the end of the bulb. One leg of filament 29 is connected to the end of the common lead wire I2 and the other leg is connected to the end of a lead wire 30 the other end of which is connected to the contact 24 in the base.

It will be apparent from the drawing that in each lamp, the filaments It, I I are located on opposite sides of the bulb axis and closely adjacent said axis while the third filament (22, 25 or 29) is located out of said axis but close thereto and is disposed symmetrically about a plane passing through said bulb axis at right angles to the plane of said filaments Ill, II. Therefore when the lamps are placed in the headlight reflector, all three filaments will be located close to the focal point thereof, thereby providing for good control over the beams projected from the headlight.

These lamps (Figs. 1-6) may be used interchangeably in various set-ups with good results but will produce particularly desirable results when used in the ways diagrammatically illustrated in Figs. 7 to 13 inclusive. These figures represent views of a pair of reflectors looking from the drivers seat of the vehicle and illustrate diagrammatically the position of the filaments. In each case the lens shown in Fig. 14 must be placed in front of the right reflector, and the lens shown in Fig. 15 in front of the left reflector to produce the light beams as they are illustrated. The terms right and left designate the headlamps as viewed from the drivers seat. These lenses differ only in the direction and amount of their horizontal light spreading capabilities. Areas 32, 33, 34, and 35, 36, 31, as shown in Figs. 16 and 17, are covered with prisms which bend the light down, and areas 38, 39, and 40, 4| have no downward bending prisms. The prisms in areas 32, 34, and 35, 31 are preferably progressive in design while the prism or prisms in areas 33 and 36 need not be progressive because their bending action is slight. By progressive design I mean that the surface of the prism is curved instead of plane to form a combination prism and lens which provides a progressive increase in the angle of bending and which in addition to bending the light, also spreads it, thus producing a smooth beam. These prisms direct the light in substantially only the vertical direction and may be incorporated in one face of the lens, as shown, or in the so-ealled horizontal spreading flutes on the other surface thereof.

The spreading flutes in the right lens R II (Figs. 14, 18 and 19) comprise half flutes with a spreading action of about 6 which are disposed over areas 38, 39 and 33 and which throw the light to the right from the drivers seat, and full flutes with a spreading action of about 20 which are disposed over areas 32 and 34. Areas 38, 39 and 33 may comprise sideward bending prisms instead of half flutes, or sideward bending prisms in combination with half flutes. The left lens L I2 (Figs. 15, 20 and 21) has full flutes with a spreading action of preferably 6 to 8 which are disposed over areas 40 and 4|, and full flutes with a spreadingaction of to which are disposed over areas 35, 36 and 31. Other methods of easily be devised, and other lens designs for use with reflectors having both the spreading and/or bending characteristics can be used, so I do not wish to limit myself strictly to this design. I am also aware that the lenses can be placed in the opposite reflectors without, changing the beam pattern if the filaments are arranged accordingly. The headlamps used in my invention comprise a pair of parabolic or modified parabolic reflectors in which are used any of the incandescent lamps shown in Figs. 1-6.

One position of the filaments within the reflector which gives satisfactory light beams with the lamp shown in Fig. 1 is illustrated in Fig. 7. With this arrangement all the filaments are at a compromise focus, that is, all filaments are substantially equidistant from the focal point of the reflector. In this disclosure the focal point of the modified reflector is considered as the point at which a filament used in combination with a suitable lens produces the same results as a filament at the focal point of a parabolic reflector. By a modified reflector I mean a parabolic reflector modified by changing the contour of portions thereof so as to deflect light downwardly and/or spread the light laterally, to perform the function of the usual prismatic and fluted lenses placed in front of the common unmodified parabolie reflector. Three patterns resulting from this arrangement, which I have found to be particularly desirable, are shown in Figs. 22, 23 and 24. The beam patterns are shown as they appear from the driver's seat when thrown upon a screen. The various areas represented are not necessarily of a given intensity or of even intensity, as hereinafter explained. The first pattern shown in Fig. 22 represents what might be called a driving beam and is produced by using filaments I0 and/or II in the headlamp using the lens shown in Fig. 15, which in this case is the left headlamp L 4, and filament ID in the other headlamp R 4 (Fig. 7). The beam pattern produced is characterized by a so-called hot spot 44 of substantially oval cross-section, located at the center (line 42) and just below horizontal (line 43), a smaller area of less intensity directly below the first, a narrow band 46 of still less intensity just below horizontal extending to the limits of the beam, and another band of light 41 just below the band 46, running the full width of the'beam and decreasing in strength below the horizontal. The hot spot 44 is produced by lens areas 4II4I of'Fig. 15 with filaments I0 and/or I I. The pattern area 45 is produced by lens areas 33-38-39 of Fig. 14 with filament III. The band 46 is produced by lens area 36 of Fig. 15 with filaments I0 and/or II. The band 41 is produced by'lens areas 33-34 of Fig. 14 with filament I0 and lens areas 3531 of Fig. 15 with filaments I0 and/or I I. The pattern shown'in Fig. 23 may be referred to as a passing beam since some of the light is thrown to the right of center and the rest is depressed below the horizontal (line 43). Essentially this beam pattern is obtained by any of the set-ups shown in Figs. 7 to 13. The characteristics of this beam are a "hot spot 48 of substantially oval cross-section located to the right of center and just below the horizontal, a smaller area 49 of less intensity below the area 48, a shield-shaped area 50 of;still less intensity directly in the center and a few degrees below horizontal, and another band5l running the full item area 56 Fig. '15 with filament 22.

operating satanic in the right headlamp R 4 (Fig.7) and filament 22 in the left headlamp'L 417 The hot spots 48-49 are produced by lens areas 33-38-39 ofFigf14' with filament 11. The patis producedby .le'n s areas 46-41 of The band, l "is produced by'lens areas 35-36-31 of Fig. '15 filament 22 and lens areas 32-34 of Fig-14 with filament. f v The third'p'at'tern of thecombination which' may be used during'city driving is shown in Fig. 1 24land is produced by the use of filaments 22 in each headlamp. The light in this case consists of a large band 52 which covers'the full width; of the beam and is several degrees below horizontal, and a shield-shaped area 5 3 and an apioidal area '54 of approximately equal intensity. Since the area 53 is on center and just below i horizontaLand the area 54 is just to the right of center and below horizontal, they overlap to form a third area,i55, of greater intensity. The ,pattern area 53 is produced by lens areas 40-41 of Fig. 15 with filament 22. The area 541s produced by lens areas33-36-39 of Fig. 14 with filament 22. The band 52 is producedby lens areas 35-36-31 of Fig. 15 with filament 22 and lens areas 32-34 of Fig. 14 with filament 22.

This beam pattern represents substantially the city beams of allthe arrangements shown in Figs. 7 to 13.

A somewhat similar arrangement appears in Fig. 8 which illustrates the arrangement using beam pattern is like that the lamp of Fig. 3. In this lamp the thirdfilament 22 of Fig. 1 is replaced by a filament 25 of different design which doesf'not alter the beam design appreciably. It will therefore be noted that this lamp may be substituted for the other in each of the arrangements in Figs. '7 to 13 with good results, providing filaments l0 and H are in the same position in each instance. In actual v practice this lamp is p'erhapsto be preferredalthough due to lower manufacturing costs, the former lamp may be considered more important.

Another arrangement of the filaments that r gives very desirable characteristics is shownin Fig. 9. In this arrangement the lamp in the right headlamp R 6 is so placed that filament H is in the focal point of the reflector, and filament H1 is to the right and below the focal point. With this set-up the passing and city beams are substantially the same as before, but the driving shown in Fig. 25. The

characteristics of this beam are a hot spot 56 of substantially oval cross-section, located at the lens area 36 of Fig. 15 with filaments center and just below horizontal, another larger and roughly oval hot spot51 of less intensity substantially in the center and above and below horizontal, a narrow band 58 of still less intensity just below horizontal running the full width of the beam, and another band 59 also running the full width of the beam and decreasing in strength below the horizontal. The hot spot 56 is produced by lens areas 40-41 of Fig. 15 with filaments and/or II. The second hot spot 51 is produced by lens areas 33-38-39 of Fig. 14 with filament ID. The band 58 is produced by 10 and/or II. The band 59 is produced by lens areas 35-31 of Fig. with filaments l0 and/or II and lens areas 32-34 of Fig. 14 with filament Ill.

Perhaps the most preferable arrangement is that shown in Fig. 10. The left headlamp L 1 has filament H1 at the focal point of the reflector, and filament II to the left and below the focal point. The lamps may be identical, that in the rangement four .hot spot 60 is produced by The second hotspot 6| dlcated in'Flg. 10. 'The'rightheadlampjR 1 has filaments 1'0 and 'll inna horizontal plane and the fo'ca'l points With this arequidistant from n beams may, be produced. First, a driving beam shown in Fig. 26', is obtained by using filaments l0 :and- H (Fig. 10) in the left headlamp L 1, and filament Ill inthe right-headlamp R1." Then, apassing beam substantially'as' shown in Fig."23 is obtained-by using filament 22 in the :left headlamp and filament I l inthe right headlamp, and a city beam,- which is of substantially the pattern shown in Fig. 24, is obtained by the use of filament 22 in each lamp. Still another beam, chiefly 'used' for focusing and aiming the headlamps, uses filament giving substantially the pattern shown in Fig. 26

with areas GI- and. 63 removed. This latter beam" may also be used as a driving beam in suburban districts and also as a driving beam in the country when no "light above the horizontal is needed or desired. The driving beam pattern (Fig. 26)

is characterized by a ning the full width of the beam, and a wide band 64 also running the full width of the beam and decreasing in strength below the horizontal. The lens areasMl-M of Fig. 15 with filament I0. is produced by lens areas 40-41 of Fig. 15 with filament H. The third hot spot 61' isproduced by lens areas 33-38-39 of Fig. 14 with filament ID. The band 62 is produced by lens. area 36 of Fig. 15 with filament Ill and the band 63 is produced by the same lens area with filament Hi. The band 64 is produced by lens'areas 35-31 of Fig. 15 with filament ill-ll and lens areas 32-34 of Fig. 14 with filamentlfl.

By slanting the'lamps in both headlamps, as shown in Fig. 11, another arrangement'is obtained which provides passing and'city beam patterns substantially the same as in the first case, but a driving beam pattern as shown in Fig. 2'7. Said pattern of Fig. 27 is characterized by hot spot 65 of substantially oval cross-section just below horizontal and at the center, a larger hot spot 66 of less intensity above and below horizontal and substantially at the center, a narrow band 61 of less intensity above horizontal width of the beam, having an intensity at the top approximately that of the band 61 and decreasing in strength below the horizontal. The hot spot 65 is produced by lens areas 40-41 of Fig. 15 with filament ill. The second hot spot 66 is produced by lens areas 40-41 of Fig. 15 with filament H and lens areas 33-38-39 of Fig. 14 with filament ID. The band 61 is produced by area 36 of Fig. 15 with filament II, and the band 68 is produced by the same lens area with filament 10. The band 69 is produced by lens areas '35-31 of Fig. 15 with filaments l0 and H and lens areas 32-34 of Fig. 14 with filament Ill.

The arrangements shown in Figs. 12 and 13 H1 in each headlamp hot spot 66 of substantially oval cross-section located at the center and just below horizontal, another hot spot 61 of less intensity extending above andbelow horizontal,

are particularly adapted for the lamp shown in Fig. 5. The arrangement shown in Fig. 12 gives essentially the driving beam shown in Fig. 25 when usingfilaments Ill and/or II in the left headlamp L 9 and filament in the right headlamp R 9. Fig. 13 gives essentially the driving beam shown in Fig. 27 by using filaments l and il in the left headlamp L l0 and filament II in the rightheadlamp R Hi. It also gives essentially a driving beam of the form shown in Fig. 25 when. using filament II) in the left headlamp and filament II in the right headlamp. The passing beam of. each arrangement is substantially the same as that shown in Fig. 23 and is obtained by the use of filaments 29 in each headlamp. The city beam is substantially the same in each instance and is essentially that shown in Fig. 24 and is produced by the use of filament 29 in the left headlamp and filament ill in the right headlamp.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An incandescent lamp comprising a bulb having a plurality of concentrated filaments sealed therein, and a separate circuit connection for each of said filaments, two of said filaments being disposed side by side in substantialy the same plane and on opposite sides of the bulb axis and extending laterally outward from the bulb axis with their inner ends closely adjacent, and a third filament being located directly to one side of said two first-mentioned filaments and being disposed substantially symmetrically about a plane passing through the bulb axis at right angles to the plane of said two first-mentioned filaments.

2. An incandescent lamp comprising a bulb having a plurality of filaments sealed therein, and a separate circuit connection for each. of said filaments, two of said filaments being V- shaped and disposed side by side one on each side of the bulb axis to form a W and being located in a plane passing substantially through the said bulb axis, and a third filament being' located out of said bulb axis directly to one side .of said two first-mentioned filaments and being disposed substantially symmetrically about a plane passing through ,said bulb axis at right angles to the plane of said two first-mentioned filaments.

3. An incandescent lamp comprising a bulb having a pluralityof filaments sealed therein, and a separate circuit connection for each of said filaments, two of said filaments being V- shaped and disposed side by side one on each side of the bulb axis to form a W and being located in a plane passing substantially through the said bulb axis, and a third V-shaped filament being located out of said bulb axis directly to one side of said two, first-mentioned filaments in a. plane parallel to the plane of said two first-mentioned filaments and being disposed substantially symmetrically about a plane passing through said bulb axis at right angles to the said plane of said two first-mentioned filaments.

, 4. An incandescent lamp comprising a bulb having a plurality offilaments sealed therein, and a separate circuit, connection for each of said filaments, two of said filaments being V- shaped with theirapices toward the front of said bulb and disposed side by side one on each side in a plane passing substantially through the said bulb axis, and a third rectilinear filament located in a plane passing through said bulb axis at right angles to the plane of said two first-mentioned filaments, said third filament being inclined forwardly with its rearward end adjacent the adjacent ends of said two V-shaped filaments.

5. An incandescent lamp comprising a bulb having a plurality of filaments sealed therein, and a separate circuit connection for each of said filaments, two of said filaments being V-shaped and disposed side by side one on each side of the bulb axis to form a W and being located in a plane passing substantially through the said bulb axis, and a third V-shaped filament located in a plane passing through said bulb axis at right angles to the plane of said two first-mentioned filaments, one end of said third filament being located adjacent the adjacent ends of said two first-mentioned filaments.

VAL J. ROPER. 

